Tube base and socket



Jan. 14, 1936. J. HIRMANN 2,027,730

TUBE BASE AND SOCKET Original FiledAug. 16, 19515 lNvl-:Nol JULIUS HIRMANN ATTORNEY Patented` Jam 14, 1936 I l 2,027,130 TUBE msn AND socxn'r Julius Hirmann,v Hillside, N. J., assigner to Radio Corporation of America, a corporation of Delaware Original application) August 16, yi933, Serial No. 685,347. Divided and this application May 18, 1934, Serial N0. 726,229

Claims. (Cl. )33e-328)v My invention relates to vacuum tubes and the the pins, which must, of course, have a bore somelike, and more particularly to bases and sockets what larger than ,the wire. for such tubes. A reduction in the size of the conventional This application is a division of my copending socket and its contacts will result in contacts application, Serial No, 685,347, filed Augustl, which are too weak for practical use, which do 5 1933, and Patent 1,976,561 and assigned to the l not have suilicient contact area and which insame assignee as the present application. crease the diillculty of assembling the socket. It

The conventional vacuum tube has a cupwould not be practical to materially reduce the shaped base with a at bottom on which tubular size of contacts in the socket and still have these contact pins are mounted in a circle near the rim contacts properly cooperate with base pins which 10 to project perpendicularly from the bottom -of were not materially less than the conventional the base, thus adding to the overall length of the size.

tube. These tubular contactv pins are connected The conventional contact pin is in effect riveted to the electrode elements of the tube by leading-in into the base by upsetting or spinning the inner uaITED STATES PATENT OFFICE wires threaded into and soldered to the pins. end of the pin over the inside of the bottom of 15v The conventional socket has spring contacts which the base. The inner end is thus enlarged and in engage the contact pins of the base. The socket effect increases the diameter of the pin so that `contacts extend radially outward and are iasmore room is required for spacing between thev tened at their ends or intermediate their ends to pins. v As it is not feasible to reduce the diameter 2o the bottom of the socket by rivets or thelike; of the pins, the space required for fastening the 20 The socket is inherently large and bulky and pins to the base cannot be reduced, nor'can smallextends considerably beyond the outline of the er socket contacts be used as the conventional base oi the tube. socket contact is larger than the base pin.

An increase in the number of contact pins on One object of my invention is to provide a base the base decreases the spacing between the pins, and socket which can be made smaller than the 25 increases the tendency for-voltage breakdown conventional base and socket and yet have as thru the base and greatly increases the dilculty many or even more contacts of ample area and of basing the tube particularly the threading 'of properly spaced so that the electrical and methe leading-in wires into the contact .pins. The chanical properties of the smaller base and socket number of contacts which can be accommodated will meet all requirements. 30 by the conventional socket has likewise reached A further object o f my invention is to provide apractical limit because of lack of space and a base and socket having mechanically strong- 'because of the increase in the tendency of voltcontacts which are so arranged that more angular age breakdown thru the socket. Assembly of the space is made available for the contacts than in socket due t0 the number of parts required is the conventional base and socket and which are 35 likewise made more diillcult. 'made to occupy less angular space on the base Not .only has the practical limit been reach and socket than the contact pins and socket conin the number of contacts which can be mounted taets commonly used, yet have as great or even in a conventional way in tube bases and sockets greater contact areaA than the conventional pin 40 of conventional size, but tube bases and sockets and socket ammo,4 40 only about one-half the conventional sizemust Stm another objeof;` of my iirvention'is to probe made with asma-BY 0r even 111016 Contacts than vide improved base and socket contacts which the bases. and sockets of conventional size. 'I'he arejsmple and inexpensive to make,

usual number 0f OODVeIltiOnal 6011113617 Pins can' The novel features which I believe to be char- 111211V be 'mounted in the ,COIlVeDtOnal WBS' 0n the acteristicoi my invention are set forth with par- 45 smaller base, yet a corresponding reduction in ticularity in the appended claims, but the invensize 0f the 00111281013 Pins Will result in pins which Y tion itself together with further objects and adare too weak for practical use, which do not have vantages thereof, will best be understood by refenOllgh 00111594212 al'a and Which Offer great diierence to the following description taken in conoulty in the threading of the leading-in wires into nection with the accompanying drawingl in 5o 'the pins. Furthermore, there is a practical limit which:- in the reduction "of the diameter ofthe contact Figure 1 is a longitudinal cross-section of a pins and of the leading-in wires. as the wires socket constructed in accordance with my invenmust be sulciently large to carry the necessary tion with a tube having abase made in accordance current and also stiff enough to thread easily into with my invention inserted in the socket. 55

Figure 2 is a top view of the socket shown in Figure 1 with parts in section to show details of construction.

Figure 3 is a longitudinal cross-section of the empty socket of Figure 1 taken along the line v3 3 of Figure 2.

Figure 4 is a perspective view of the annular top member of the socket of Figure 3.

Figure 5 is a longitudinal cross-section of the socket shown in Figure l with the tube base partly inserted, and

Figure 6 is a perspective view of a contact and locking block made in accordance with my invention.

The vacuum tube shown in Figure 1 of the drawing has an evacuated bulb I5 which encloses the usual cathode and other electrodes, and has cemented to it a cup-shaped base I6, preferably of molded insulation. The base has radial bosses I1 spaced around its periphery near the bottom and extending lengthwise of the base. These bosses have inclined shoulders I8 at the top and tongues I9 at the bottom to position and support the base contacts.

U-shaped contacts 23 consisting of at strips or ribbons, are wrapped around and carried by the bosses I1. The ends of the contacts are brought together beneath the boss and welded to fasten the contacts in place on the bosses and to form connecting lugs 24 which facilitate and simplify the connecting of the lead wires which extend thru the bottom of the base to the base contacts 23. The lead wires may be welded to the lugs, thus making a good electrical connection more easily than by soldering and eliminating threading of the lead wires into the contact pms.

Since the width of a boss with a contact mounted on it may be less than the diameter of the conventional tubular contact, and since the contacts are spaced around the exterior of the base instead of in a circle on the bottom of the base near the rim as is done with tubular co'ntacts, more such contacts can be accommodated on a base of the usual size, or the size of the base can be materially reduced and still the maximum number of contacts now feasible for the usual size base can be used. These at contacts are strong and provide ample contact area.

The contact membersv 23 may to advantage be made of nickel which can very easily be worked land welded. By mounting the contacts on the bosses projecting radially from the side of the base the overall length of the based tube is made materially less than that of a similar tube having tubular contacts in the bottom of the base.

It is obvious that the base can be registered with the socket in various Ways, for example, by

a stud or projection on. the base shell to enter a corresponding slot in the socket, by one boss of different size than the other bosses, or preferably by spacing two of the bosses further apart than the others.

A socket constructed in accordance with my invention and adapted for use with the tube base above described is shown in Figures 1 to 5 inclusive. It has a metallic cup-shaped member 26 with a central stub 2'I in the bottom and a flange like lip 28. The metal cup 26 is an electrical shield for the tube base and thus assists in preventing interstage coupling which is highly desirable in modern apparatus usingl highly sensitive tubes.-

Supported on the flange like lip .8 is an annular or ring-shaped member 29 preferably riveted to the lip. 'Ihe annular member 29 overhangs the interior of the cup-shaped member 26 and has radial undercut slots or grooves 30, best shown in Figure 4. These slots 30, which are 5 enlarged or cut deeper at 3l adjacent the opening in the annular member 29, also have transverse depressions or grooves 32 by means of which the socket contacts 33 are positioned in the slots.

Each socket contact is positioned in one of the 1o undercut slots 30, and has on its outer end a lug 34 and on its inner end a downwardly extending tongue 35 positioned in the enlarged end 3l of the slot. 'I'he socket contact is formed with a hump 36 to t into a groove 32. An insulating 15 block 31, with a projection 33 for registering with the groove 32, is clamped between the socket contact 33 and the flange like lip 28 to' lock the socket contact in place. No rivets, or-bolts or the like are needed to directly fasten the contacts to 20 the socket. The contact spring need not be punched for a rivet or bolt, hence the spring contact is stronger and it may be made more y compact than has heretofore been feasible. The

contact members 33 may to advantage be made 25 of nickel which can be very easily worked or welded. They may be made in various ways, but I prefer to cut them from metal ribbon and form them as shown in Figure 6. f

As best shown in Figure 2 longitudinal slots 39 30 on the inside of the annular member 29ipermit a tube base such as shown in Figure 1 to be inserted in the socket. A protector disc 40 normally held against the bottom of the annular member 29 by a biasing spring 4I centered on the stub 21 35 prevents the entrance of foreign objects into the empty socket, and lessens the possibility of accidentally touching the socket contacts. The socket may be attached to a sub-panel 42 by means of nuts and bolts 43, as shown in Fig- 40.

ure 1. I

When the base is inserted in the socket, the bosses are registered with the slots 39, andthe tube is pushed down into the socket against the disc 40 until the tops of the bosses clear two 45 downwardly projecting lugs b and c provided on the annular member to insure that the boes will not accidentally engage and twist the tongues 35 of the contacts while the base is being rotated into place. Another downwardly extend- 50 ing lug d, which is longer than lug b and c, prevents rotation of the base in a counter clockwise direction, as viewed in Figure 2, but permits rotation of the base in a clockwise direction to bring the contact tongues 35 on the socket and 55 the contacts 23 on the base vinto alignment. When this position has been reached, pressure is released from the tube and the biasing spring 4I forces the base I6 up against the tongues 35 of the contacts `33 as clearly shown in Figure 1 to 60 provide electrical contact between the base and socket, the tongue 35 giving an inward wiping action as the biasing spring pushes the base into place. This locks the tube base in the socket and prevents poor operation of the 'tube due to loose 65 contacts brought about by shock and jar, thus making this construction highly satisfactory for mobile and portable use.

It wwill thus be seen that I have provided a base and socket in which the maximum number of 70 contacts which is now feasiblegto use on the conventional base and socket can be materially increased and still have the base and socket fully` meet the electrical and mechanical requirements of such tube bases and sockets. In ac- 76 `mobile use.

cordance with my invention I can materially reduce the size of the usual base and socket and still properly accommodate as many contacts as can now be used on the base and socket of usual size. In addition to providing an improved method of attaching the contacts to the socket, the socket electrically shields the tube base and securely retains the tube base in place against the usual vibration and shock encountered in portable and The shielding vand wide spacing of the contacts which reduces interlead capacity also makes a base and socket embodying my invention most suitable for short wave use.

While I have indicated the preferred embodiments of my invention of which I am now aware I and have also indicated only one specific application for which my invention may be eml ployed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be madein the particular structure used and the purpose for which it is employed without departing from thescope of my invention as set forth in the appended claims.

What is claimed as new is 1. A socket for a vacuum tube having spaced contact'suppo'rting bosses on the periphery of the base, including a cup-shaped member having an outwardly extending ange like lip, an annular member supported on said lip and overhanging the interior of said cup-shaped member, spaced radial contact members supported on the under side of said annular member and insulated from said cup shaped member and overhanging said cup-shaped member to a less extent than said annular member, said annular member being provided with interior longitudinal slots intermediate said contacts to permit the insertion of the base into the socket, and means for biasing the base to force the contacts on the base against thecontacts in the socket.

2. A socket for a vacuum tube having spaced contact carrying bosses on the periphery of the base, including a cup-shaped member having -a ange like lip, an annular member supported on said lip and overhanging the interior edge of said cup-shaped member, said annular member having radial under-cut grooves, contact members supported within said grooves insulated from said cup shaped member and overhanging the interior edge of said cup-shaped member, said annular member being provided with longitudinal slots intermediate said grooves to permit insertion of the tube base in said socket, stop means on the under side of said annular member cooperating with the bosses on the tube base for permitting limited rotation of said base in one direction only to align the contacts on the base and in said socket and means for biasing the base to engage the base and socket contacts.

3. A vacuum tube socket including a cupshaped member having a flange like lip, an insulating annular member supported on said lip and to overhang the interior of said cup-shaped member, said annular member having radially directed under-cut slots groove intermediate its ends,

provided with a transverse,

a spring contact mounted in said slot and having an intermediate portion formed to fit in said transverse groove, and a block of insulating material clamped between said ange like lip provided with a projection thereon registering with the intermediate portion of said spring contact for locking said contact in said annular member.

4. A vacuum tube socket including a metal cupshaped member provided with a flange like lip, an

annular member of insulating material supported on saidlip to overhang the nteriorof saidvcupshaped member, said annular member being provided With spaced under-cut radial slots, flat and said contact, and

spring 'contact members in said slots and insu lated from said cupshaped member and over-V hanging the interior of said cup-shaped mem ber to a less extent than said annular member, said annular member being provided with spaced longitudinal slots intermediate said under-cut slots to permit the insertion into said socket of a base having Contact carrying longitudinal bosses on its periphery, and means for against the contacts in the socket to engage the base and socket contacts.

5. A socket for a vacuum longitudinal contact carrying bosses on the periphery of the base, including a metal cup-shaped member, an annular member mounted on said cup-shaped member to overhang the interior of said cup-shaped member, said annular member having radial under-cut grooves enlarged at the inner ends, contacts insulated from said metal cup-shaped member and supported within said grooves to overhang the interior of said cupshaped member and to `permit free movement of the inner ends of said contacts, said annular member having longitudinal slots intermediate said grooves to permit the insertion of the tube base, and a disc biased against the under side of said annular member to close the opening into the interior of said cup-shaped member.

JULIUS HERMANN.

biasing the base Ti tube having spaced I 

